CELTICS NOTEBOOK: One-quarter mark of the season arrives

The Celtics have the best record in the NBA after their first 20 games.

Jim Fenton The Enterprise @JFenton_ent

BOSTON – The one-quarter mark of the 2017-18 season has arrived for the Celtics this weekend, and it’s already been a wild ride.

They lost Gordon Hayward to a gruesome season-ending injury on opening night, then ripped off 16 straight wins after a 0-2 start.

The Celtics, who hosted the Orlando Magic Friday night, have the best record in the NBA, but coach Brad Stevens has seen flaws in his team, particularly at the offensive end.

While the Celtics have been the best defensive team in the league, their offense has struggled, and early double-digit deficits have occurred over and over.

“We need to play better offense,’’ said Stevens. “We need to focus on being a little more crisp on that end.’’

The Celtics have gotten off to slow starts, saving their best basketball for the second half.

“That’s been a lot of our focus and a lot of the time we’ve been talking, when you look at our first half vs. our second half, it’s night and day,’’ said Stevens. “One of the things we need to do is play better in the first half and, secondly, we need to get the ball from side to side. That’s usually a good indicator that we’re going to get a good attack.’’

The Celtics kept overcoming leads to keep their winning streak alive before falling just short in Miami Wednesday night.

“The biggest thing is that we need to be focused on how we can continue to play as well as we can,’’ said Stevens. “The resolve and the grit of this team has been pretty special throughout the first 19 games. What that means moving forward, we’ll see.

“But we’ve got to play better basketball for more portions of the game. I didn’t think the streak took any emotional toll. I didn’t hear anybody talking about it. They stayed in the moment and played the next game.’’

Around the rim: The Celtics wore black uniforms with green trim for the first time against the Magic. “I don’t really pay attention to our uniform colors unless we’re throwing it to the wrong team over and over,’’ joked Stevens. ... Orlando coach Frank Vogel, a former Celtics assistant, had high praise for Al Horford. “Probably the most underrated guy in the league, in my opinion with everything he does,’’ said Vogel. “He plays the four, plays the five, holds the fort down blocking shots, plays a switching defense, (leads) communication on that end of the floor. He doesn’t have that superstar persona that in my mind he is.’’

Little prep time: With the Bruins playing Friday afternoon, the Celtics had to wait to get on the parquet floor for pregame workouts.

“If we had a couple of days off prior to (Friday), we may have shot around at 11 (a.m.),’’ said Stevens. “But getting in late on Wednesday night, I didn’t want to get them up again this morning.

“I thought rest was really important, so we did a film session here as they were starting to (change to) the court. We walked through in one of the media (rooms) that we use for the playoffs. We’ve done that in the past. It’s a part of it.’’

On the road: The Celtics, who just finished a three-game road trip Wednesday, were back on a plane late Friday night.

They face the Pacers in Indiana Saturday (8:05 p.m., TV: NBC Sports Boston; radio: WBZ-FM/98.5), then play five straight games at home